Las Vegas hosted one of its best pool parties of the year last night as Night 2 of SPF 2017 kicked at The Cosmopolitan of Las Vegas’ Boulevard Pool.

While this year’s edition of the venerable Sin City summer event wasn’t offering the blistering temperatures visitors usually expect (a relatively moderate 88-degree high on show day, thank you very much), the overwhelmingly upbeat, ridiculously attractive roster of SPF talent, coupled with an eager-to-party audience, generated plenty of heat all on their own.

As show openers go, it isn’t often you’ll find a leadoff act with a fan following to rival anyone else on the bill. However, Niall Horan, formerly of boy band supergroup One Direction, isn’t your usual solo artist waiting to drop his first album.

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With an output of only two singles and a debut album months away from release, Horan is still building a reservoir of songs for a full live solo performance. However, his three-song warm-up set at SPF, including his first hit “This Town” and the newly released “Slow Hands,” was greedily received by the poolside faithful.

A contingent of enthusiastic female fans were the most vocal appreciators of Horan’s set, with many happily pressed up against the edge of the stage, screaming their approval during Horan’s heartfelt and lively performance.

“I miss (Las Vegas),” said Horan, who acknowledged he celebrated his 21st and 22nd birthdays in the Nevada desert town. “It’s gonna be a good night,” he smiled.

Following Horan, rapper/singer/songwriter/producer Post Malone may not have generated the same levels of lusty encouragement Horan received, but the 21-year-old’s natural charm, infectious smile and feel-good vibe immediately won over the SPF crowd.

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Asking if “you don’t mind if I drink, do ya,” the perpetually grinning, Texas-raised star commanded the stage with obvious ease, unfurling a laid-back, trippy set that instantly found a handhold with an audience ready to coast through the journey with him.

Whether he was strumming a guitar on “Go Flex,” leading an impromptu “saucin’…swaggin’…ballin’” singalong on his breakout hit “White Iverson” or getting fans swaying with the chill-out feels of his latest single and set closer “Congratulations,” Malone was a quick fan favorite who could now undoubtedly score party invites and posse status with any of the poolside crowd by his set’s end.

Malone gave way to the night’s major surprise as SPF was rocked by an unannounced set from another young explosive wunderkind, Dutch DJ megastar Martin Garrix. Thrilled with the surprise appearance, the audience slid effortlessly into dance mode, head bobbing and body-hopping to Garrix’s tight three-song set, capped by his Bebe Rexha collaboration “In the Name of Love.” Garrix even flashed an almost embarrassed smile as he was presented with a giant mixer-shaped cake in honor of his 21st birthday that week.

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After the steady stream of men rocking the poolside venue, it was time for some girl power to grip the stage, coming in the form of Oscar nominee turned pop powerhouse, Hailee Steinfeld. Flanked by a squad of dancers, the Pitch Perfect star sank her teeth into a focused 15-minute barrage that clearly spoke passionately to the girls and young women screaming with adoration.

From her chart-topper “Starving” to the insidiously bouncy “You’re Such A” and “Love Myself,” Steinfeld was in such high spirits as she embodied female empowerment, cresting in her set-closing ode to the awesomeness of ladies everywhere with “Most Girls.”

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Returning to the SPF stage for his second year, 27-year-old Jason Derulo pulled out all the stops for his hot and sexy performance.

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Following a five-minute adrenaline power-up driven by his personal DJ/hype man Jae Murphy, Derulo finally thrust his hyper-sexy brand of ferocity and sensual power onto the stage with a rollicking version of “Trumpets,” immediately wrapping SPF-ers into his seductive web.

“I heard that this is the hottest f—ing party on the planet right now,” Derulo playfully offered. It was a claim lustily confirmed as booty-shaking took center stage during Derulo’s love of big bumpers anthem “Wiggle,” his open invitation to carnal fun (and latest single) “Swalla” and club pick-up tutorial “In My Head.”

That when Derulo’s shirt came off…and all the foreplay got seriously serious in a sexed-up-to-11 double shot of “Talk Dirty” and his super-charged earworm of a hit “Want To Want Me.”

By the time Derulo left the stage, there were only a few minutes for a post-coital cigarette and a brief cooldown before the clock struck midnight and the evening’s headliners DNCE attacked.

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Striding on stage wearing Darth Vader helmets to the strains of John Williams’ classic “Star Wars” fanfare, Joe Jonas and company set a playful, freewheeling tone from the jump, infusing their nearly hour-long set with a whimsical, anything-goes tone that served as a perfect capper to night’s festivities.

After ripping through funky, aroused opener “Body Moves,” Jonas surveyed the crowd carefully before slyly observing, “Gotta say…this is a sexy crowd out there.” The SPF audience agreed, diving headlong into DNCE’s irreverent, sugar-rush of a performance, jaunting through house party mashers like “Blown.”

The set even deployed appreciative nods to pop gems of the past that infuse DNCE’s catalog, including a minute or two of the David Bowie classic “Let’s Dance” before leading into their own irresistible singalong candidate “Good Day.” Brief eclectic snippets of far-flung hits like The Guess Who’s “American Woman” and even Britney Spears’ “Toxic” peaked out from behind the band’s infectiously likable set. It all culminated in a quick cover of throwback Spice Girls’ smash “Wannabe” before segueing into a four-song show-closing barrage, including new single “Kissing Strangers” and bounce-happy gem “Cake By the Ocean.”

As “Cake”’s final chords brought the evening to a close just after 1:00 AM, even fans who didn’t snag one of the DNCE t-shirts Jonas launched like rocket volleys into the crowd went home happy and satisfied from the amazing night of music.